Breathing the air in Greater Cincinnati kills about 300 people every year.

That's the conclusion of a 40-page national report from Abt Associates Inc., a U.S. Environmental Protection Agency consultant hired by two national environmental groups to study human health effects related to coal-fired power plant emissions.

The report says that the Cincinnati-Middletown area has the most unhealthful air in Ohio, and is 10th worst in the nation when it comes to people suffering fromheart attack and premature death related to air pollution.

The report concludes that by 2010, in Greater Cincinnati there will be 319 premature deaths every year related to power plant emissions, 517 heart attacks, 44 lung cancer deaths and 1,908 asthma attacks.

Ohio ranked second worst in the nation for premature deaths and heart attacks relating to power plant emissions, according to the report. Three Ohio cities (Cincinnati, Cleveland and Columbus) ranked among the 16 worst metro areas nationally.

"Whether it's premature deaths, asthma attacks or heart attacks, Ohioans are suffering the damaging effects of power plant air pollution more than nearly any other state," the report says.

Scott Segal, who represents several major utilities, said the report obscures the fact that power plants have significantly reduced most forms of pollution. For example, the amount of particulate matter, or soot, in the air has dropped 75 percent nationwide from 1970 to 1999. And that reduction happened during a period when energy consumption rose by 41 percent, he said.

The study relied on computer modeling to compare EPA data on power plant emission levels and dispersal patterns with results of epidemiological studies by Harvard University in 1993 and the American Cancer Society in 1995.

Environmental activists say the Bush Administration has weakened or delayed implementation of air pollution laws. Tough enforcement of current laws, they say, would result in 4,000 fewer premature deaths every year, which the study says will reach 22,000 by 2010.

"Cincinnati families need clean air to breath, but by failing to enforce existing Clean Air Act health protections on Ohio's dirty coal-fired power plants, the Bush Administration is putting our health at risk," said Glen Brand, the Sierra Club's Midwest regional representative, who lives in Cincinnati.